America's Top Selling Prescription Drugs

More From Healthy Business 2011

Best Selling Prescription Drugs

The pharmaceutical business is an extremely profitable one. According to the IMS Institute for Healthcare Informatics, spending on medicine in the U.S. alone exceeded $307 billion in 2010. For many drug makers, one money-spinner can carry a company for years, even longer, before the patent expires and low-cost generic versions can be made.

The IMS recently released its annual list of the ten top-selling drugs in the US, based on sales. Each of them have brought in at least $3 billion dollars.

However, a majority of these drugs will lose patent protection in the next five years. Generic versions will quickly dent sales and revenue.

Here's a look at their sales, when their patent protection expires and which generic drug makers will offer alternatives.

IMS data is based on only U.S. sales and wholesaler invoice prices; it does not reflect off-invoice discount and rebates, thus total dollar sales numbers almost always exceed those provided by the manufacturers themselves.